Method of bending several pieces oe wood oe unequal length at once



STAR

aren' METHOD OF BENDING SEVERAL PIECES OF WOOD OF UNEQUAL LENGTH AT ONCE.

Specification of Letters Patent No. 19,538, dated March 9, 1858i.

To all whom it may concern.'

Be it known that I, H. A. BARNARD, of Moline, in the county of Rock Island and State of Illinois, have invented a new and useful Improvement in Clamps for Bending Timber, the construction and operation of which I have described in the following specification and illustrated in the accompanying drawings with sufcient clearness to enable competent and skilful workmen in the arts to which it pertains or is most nearly allied to make and use my invention.

It is well known that timber is liable in being bent-especially when the steaming is at all imperfect-to break on the outside ofthe curve around which it is bent, by the expansion of the wood on the outside of the article bent. lVood will support a greater crushing force than it will tensile strain. The result above stated is frequently the consequence when it is bent around a very short Curve unless precautions are taken to prevent it. To. obviate this difficulty is the object and purpose of my invention.

My said invention consists in combining a clamp, so constructed, as to grasp several pieces of timber at the same time by taking hold of them upon the sides of the sticks; with a supporting strap of sheet metal; and the bending frame, by which I overcome the tensile force upon the outer strata of the wood and t-hus preserve it from fracture.

' In t-he accompanying drawing Figure l is a plan of my improved bending machine. Fig. 2 is an elevation of the same.

A is the frame of the machine, B is the main bending wheel hung upon a shaft- C. This wheel is operated by a strap D, passing around it and running over the pulley E upon the shaft F which has a crank Cr attached to it, which is grasped by the operator to turn the wheel B. One end of the shaft C is square and upon this square portion the bending model or frame I-I is placed. This bending frame I-I has a thin piece of metal I attached to it in a substantial manner, which strip I is also firmly attached to the clamp J. This clamp J has a fixed jaw K and a movable jaw L which embrace the timber M. This movable jaw L is operated by a screw N, operated by the crank O.

The timber is held up to the frame or form by an adjustable roll-er P operated by the lever Q and may be held by the foot of the operator, but if the form be circular and concentric and the timber of even thicl ness, it may be held by a pawl and rack.

The arrangement described secures the timber firmly in its position, (as the clamp J can be closed to any degree of tightness,) and is held in that position until it is bent into shape, the strip of metal I preventing the expansion of the fibers of the outer strata of the wood and their consequent rupture.

After the timber is bent and secured the clamp and frame may be taken off the shaft C; another set put on and the operation repeated.

I am aware that efforts have been made to prevent the expansion o-f the outer fibers in bending sticks of timber, by fitting a piece of timber between two stops upon the ends of a strip of metal; but this method is inconvenient, as the sticks are not always of a uniform length, as uniformity in this respect is very difficult to attain in practice. By this method, however, of securing the timber, uniformity is dispensed with and the timber secured much more conveniently and in a better manner for bending.

The particular' improvement which constitutes my said invention and which I claim as having been originally and firstvinvented S. F. Honors, LEVI PERSONS. 

